| // { dg-do compile { target c++23 } } |
| // { dg-add-options no_pch } |
| |
| #include <utility> |
| |
| #ifndef __cpp_lib_forward_like |
| # error "Feature-test macro for forward_like missing in <utility>" |
| #elif __cpp_lib_forward_like != 202207L |
| # error "Feature-test macro for forward_like has wrong value in <utility>" |
| #endif |
| |
| template<typename T, typename U> |
| using forward_like_t = decltype(std::forward_like<T>(std::declval<U>())); |
| |
| #if 0 |
| using std::is_same_v; |
| #else |
| #include <concepts> |
| template<class T, class U> concept is_same_v = std::same_as<T, U>; |
| #endif |
| |
| static_assert( is_same_v<forward_like_t<int, long>, long&&> ); |
| static_assert( is_same_v<forward_like_t<int&, long>, long&> ); |
| static_assert( is_same_v<forward_like_t<int&&, long>, long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<const int, long>, const long&&> ); |
| static_assert( is_same_v<forward_like_t<const int&, long>, const long&> ); |
| static_assert( is_same_v<forward_like_t<const int&&, long>, const long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<int, const long>, const long&&> ); |
| static_assert( is_same_v<forward_like_t<int&, const long>, const long&> ); |
| static_assert( is_same_v<forward_like_t<int&&, const long>, const long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<const int, long&>, const long&&> ); |
| static_assert( is_same_v<forward_like_t<const int&, long&>, const long&> ); |
| static_assert( is_same_v<forward_like_t<const int&&, long&>, const long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<int, const long&>, const long&&> ); |
| static_assert( is_same_v<forward_like_t<int&, const long&>, const long&> ); |
| static_assert( is_same_v<forward_like_t<int&&, const long&>, const long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<const int, long&&>, const long&&> ); |
| static_assert( is_same_v<forward_like_t<const int&, long&&>, const long&> ); |
| static_assert( is_same_v<forward_like_t<const int&&, long&&>, const long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<int, const long&&>, const long&&> ); |
| static_assert( is_same_v<forward_like_t<int&, const long&&>, const long&> ); |
| static_assert( is_same_v<forward_like_t<int&&, const long&&>, const long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<volatile int, long>, long&&> ); |
| static_assert( is_same_v<forward_like_t<volatile int&, long>, long&> ); |
| static_assert( is_same_v<forward_like_t<volatile int&&, long>, long&&> ); |
| |
| static_assert( is_same_v<forward_like_t<const int, volatile long>, |
| const volatile long&&> ); |
| static_assert( is_same_v<forward_like_t<const int&, volatile long>, |
| const volatile long&> ); |
| static_assert( is_same_v<forward_like_t<const int&&, volatile long>, |
| const volatile long&&> ); |
